Search found 65 matches

by pakman
Sat Feb 09, 2019 8:42 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Ok. Now assemble U1, U2 and U6, and try to boot.
by pakman
Sat Feb 09, 2019 8:29 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Try to boot with just 3, 4 and 5
by pakman
Sat Feb 09, 2019 7:10 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

That's the wrong JED file!
The read back JED is "V4_50ac" (thats an older revision).
Please use "P4_52", which I have sent.

And please check the other GALs as well, make sure its the latest revision.
by pakman
Fri Feb 08, 2019 10:39 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Both sounds good to me. Please read back the JEDEC from the GAL U4 and send it to me.
by pakman
Fri Feb 08, 2019 10:30 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Strange. The only explanation I see is that something went wrong with the programming.
Which GAL and which programmer are you using?
by pakman
Fri Feb 08, 2019 10:19 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

The very same U4 as before? Or a new U4?
by pakman
Fri Feb 08, 2019 10:10 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Let's fix U4 first. Get another GAL (not the U4 you are using right now), program the P4 JEDEC, and try again to boot.
by pakman
Fri Feb 08, 2019 10:02 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

That's weird. Check the voltage at U4 pin13, should be high. Then all outputs of U4 should be tri-stated, essentially the same as if there were no U4 at all.
by pakman
Fri Feb 08, 2019 9:47 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Ok, add GAL U4 and try to boot
by pakman
Fri Feb 08, 2019 9:36 pm
Forum: HARDWARE ISSUES
Topic: PAK issues
Replies: 160
Views: 22552

Re: PAK issues

Next: Remove the U5 jumper wire, and assemble U5 instead. Try to boot.

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